Medicine: Return of the Philly Killer

At first the patients seemed to be suffering from simple pneumonia. But
when doctors at the Medical Center Hospital of Vermont in Burlington
investigated further last August, they realized that they were probably
dealing with something more puzzling and dangerous. As Dr. Harry Beaty,
the hospital's chief of medicine, recalls, the symptomsdry cough,
abdominal pain, general malaise "were defying all our usual concepts
of pneumonia." So he promptly sent off blood samples to Atlanta's
Center for Disease Control (CDC). A few weeks later the center's
sleuths...